当我站在悬崖边时，我能感觉到血液在我的血管中奔流。

I could feel the blood pulsing through my ___veins as I stood at the edge.

医生费了好大劲才在我手臂上找到一根血管来插入针头。

The doctor struggled to find a ___vein in my arm to insert the needle.

在她苍白的皮肤下，隐约可见如蛛网般的纤细蓝色血管。

A spider web of tiny blue ___veins was visible just beneath her pale skin.